Key Laboratory of Sensor Analysis of Tumor Marker, Ministry of Education, Shandong Key Laboratory of Biochemical Analysis, Key Laboratory of Analytical Chemistry for Life Science in Universities of Shandong, College of Chemistry and Molecular Engineering , Qingdao University of Science and Technology , Qingdao 266042 , People's Republic of China.
Anal Chem. 2019 Jan 2;91(1):983-989. doi: 10.1021/acs.analchem.8b04116. Epub 2018 Dec 12.
A sensitive and reliable bimodal electrochemiluminescent (ECL) system based on CdTe quantum dots (QDs) and luminol as double luminophores is constructed. CdTe QDs tagged with the aptamer (CdTe-Apt 2) of cancer cells are used as the detection signals, while luminol molecules are used as internal standards. The electrodeposited polyaniline-based conducting polymer hydrogel (CPH) on the electrode surfaces improves the biocompatibility and conductivity of the sensing interfaces effectively. Furthermore, electron transfer is probably much easier when luminol and coreactant potassium persulfate (KSO) are immobilized in the CPH in comparison to that in solution. Cancer cells are captured to the electrode surface by another aptamer linked to the Au nanoparticles immobilized in the CPH through Au-S bonds. In the developed bimodal ECL system, an internal standard method is used to quantify cancer cells by comparing the differences in sensitivity of the double-peak ECL signals with that of target analytes. The internal standard method of ECL strategy can provide very accurate detection results in a complex environment because interferences in the system can be eliminated through the self-calibration of two emission spectra. A linear relation is found on the basis of a plot of the ΔECL/ΔECL against the concentration of cancer cells within 100-6500 cells mL under optimized conditions. The developed ratiometric ECL cytosensor with internal standard can significantly improve the accuracy and reliability of cell assays in complex biological media, demonstrating promising applications in healthcare monitoring and clinical diagnostics.
构建了一种基于碲化镉量子点（CdTe QDs）和鲁米诺作为双发光体的灵敏可靠的双模态电化学发光（ECL）系统。CdTe QDs 被标记为癌细胞的适体（CdTe-Apt 2），用作检测信号，而鲁米诺分子用作内标。电极表面电沉积的基于聚苯胺的导电聚合物水凝胶（CPH）可有效提高传感界面的生物相容性和导电性。此外，与在溶液中相比，当将鲁米诺和共反应物过硫酸钾（KSO）固定在 CPH 中时，电子转移可能更容易。通过 Au-S 键将与固定在 CPH 中的 Au 纳米粒子连接的另一种适体捕获癌细胞到电极表面。在开发的双模态 ECL 系统中，通过比较双峰 ECL 信号与目标分析物的灵敏度差异，使用内标法来定量癌细胞。ECL 策略的内标法可以在复杂环境中提供非常准确的检测结果，因为通过两个发射光谱的自校准可以消除系统中的干扰。在优化条件下，基于 ΔECL/ΔECL 与 100-6500 个细胞 mL 范围内癌细胞浓度的关系图，可以发现线性关系。具有内标物的比率型 ECL 细胞传感器可以显著提高复杂生物介质中细胞测定的准确性和可靠性，在医疗保健监测和临床诊断方面具有广阔的应用前景。
